J/ApJ/809/129 The Be phenomenon. V. MWC728 (Miroshnichenko+, 2015)
Toward understanding the B[e] phenomenon
V. Nature and spectral variations of the MWC 728 binary system.
Miroshnichenko A.S., Zharikov S.V., Danford S., Manset N., Korcakova D.,
Kricek R., Slechta M., Omarov C.T., Kusakin A.V., Kuratov K.S.,
Grankin K.N.
<Astrophys. J., 809, 129 (2015)>
=2015ApJ...809..129M 2015ApJ...809..129M (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, spectroscopic ; Equivalent widths ; Stars, Be ;
Spectroscopy
Keywords: binaries: spectroscopic; stars: emission-line, Be;
stars: individual: MWC 728
Abstract:
We report the results of a long-term spectroscopic monitoring of the
FS CMa type object MWC 728. We found that it is a binary system with a
B5Ve (Teff=14000±1000K) primary and a G8III type (Teff∼5000K)
secondary. Absorption line positions of the secondary vary, with a
semi-amplitude of ∼20km/s and a period of 27.5 days. The system's mass
function is 2.3x10-2M☉, and its orbital plane is
∼13°-15° tilted from the plane of the sky. The primary's
vsini∼110km/s, combined with this tilt, implies that it rotates at a
nearly breakup velocity. We detected strong variations of the Balmer
and HeI emission-line profiles on timescales from days to years. This
points to a variable stellar wind of the primary in addition to the
presence of a circum-primary gaseous disk. The strength of the
absorption-line spectrum, along with the optical and near infrared
(IR) continuum, suggest that the primary contributes ∼60% of the
V-band flux, the disk contributes ∼30%, and the secondary contributes
∼10%. The system parameters, along with the interstellar extinction,
suggest a distance of ∼1kpc, that the secondary does not fill its
Roche lobe, and that the companions' mass ratio is q∼0.5. Overall, the
observed spectral variability and the presence of a strong IR-excess
are in agreement with a model of a close binary system that has
undergone a non-conservative mass-transfer.
Description:
Optical spectroscopic observations of MWC 728 were obtained between
2004 December and 2015 February. We have obtained 116 spectra with a
range of spectral resolving powers of R=10000-65000 and
signal-to-noise ratios from ∼30 to ≥200.
Objects:
-------------------------------------------------
RA (ICRS) DE Designation(s)
-------------------------------------------------
03 45 14.71 +29 45 03.2 MWC 728 = HD 281192
-------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table4.dat 34 116 Properties of the Hα line in the spectra
of MWC 728
--------------------------------------------------------------------------------
See also:
J/PASP/126/469 : PolarBase catalogue of stellar spectra (Petit+, 2014)
J/A+A/537/A146 : Stellar models with rotation. 0.8<M<120 (Ekstrom+, 2012)
J/A+A/537/A120 : Rotational velocities of A-type stars. IV. (Zorec+, 2012)
J/MNRAS/400/518 : Velocity & proper motion of OB associations (Melnik+, 2009)
J/A+A/501/297 : Effective temperatures of B Supergiants (Zorec+, 2009)
J/A+A/487/1129 : Evolutionary models of binaries (Van Rensbergen+, 2008)
J/A+A/479/827 : UBVR light curves of weak-line T Tauri stars (Grankin+, 2008)
J/MNRAS/363/1111 : Tycho-2 stars with IR excess (Clarke+, 2005)
J/A+A/440/305 : Fundamental param. of fast-rotating B stars (Fremat+, 2005)
J/A+A/408/305 : Spectroscopic obs. of delta Sco (Miroshnichenko+, 2003)
J/A+A/384/145 : Compiled cat. of Per OB2 star forming complex (Belikov+, 2002)
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.3 d JD [3363.7/7065.6] Julian Date; JD-2450000
10- 13 F4.2 --- Iv [1.9/7.3] Blue emission peak intensity
in continuum units
15- 19 F5.2 --- Ir [3.5/12.5] Red emission peak intensity
in continuum units
21- 24 F4.1 0.1nm EW [14.7/62] Equivalent width; Angstroms
26- 30 F5.3 --- Phase Orbital phase
32- 34 A3 --- Obs Observatory identifier code (1)
--------------------------------------------------------------------------------
Note (1): Observatory identifier code as follows:
CFH = Canada-France-Hawaii Telescope,
SPM = Observatorio Astronomico Nacional San Pedro Martir,
MCD = McDonald Observatory, OND - Ondrejov Observatory,
TCO = Three College Observatory.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Miroshnichenko A.S. Paper I. 2007ApJ...667..497M 2007ApJ...667..497M
Miroshnichenko et al. Paper II. 2007ApJ...671..828M 2007ApJ...671..828M
Miroshnichenko et al. Paper III. 2009ApJ...700..209M 2009ApJ...700..209M Cat. J/ApJ/700/209
Carciofi et al. Paper IV. 2010ApJ...721.1079C 2010ApJ...721.1079C
Miroshnichenko et al. Paper V. 2015ApJ...809..129M 2015ApJ...809..129M This catalog
Khokhlov et al. Paper VI. 2017ApJ...835...53K 2017ApJ...835...53K
Khokhlov et al. Paper VII. 2018ApJ...856..158K 2018ApJ...856..158K Cat. J/ApJ/856/158
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 10-Dec-2015